Developers are hitting a problem due to tools.jar when using Checkstyle

See https://lists.opendaylight.org/pipermail/odlparent-dev/2016-May/000321.html .. in a project using Checkstyle, we're seeing developers on Macs hitting a problem due to tools.jar:

[ERROR] Failed to execute goal
org.apache.maven.plugins:maven-checkstyle-plugin:2.16:check (check-license) on project root: Execution check-license of goal
org.apache.maven.plugins:maven-checkstyle-plugin:2.16:check failed: Plugin org.apache.maven.plugins:maven-checkstyle-plugin:2.16 or one of its dependencies could not be resolved: Could not find artifact com.sun:tools:jar:1.7.0 at specified path /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/../lib/tools.jar -> [Help 1]

To me this seems a fairly major problem, do you agree? Note that appears simply when using Checkstyle as a normal dependency (of maven-checkstyle-plugin, but that's not the main point), and NOT just when developing on/contributing to Checkstyle's own code base (which would be minor, if none of you use Macs; I don't either!).

I'll just have a look at the checkstyle pom.xml and see if something could be done about this.

@romani would you potentially consider releasing a 6.16.x maintenance release with a fix, if I contribute one for master? The FLOSS project I'm involved in cannot easily upgrade to 6.19-SNAPSHOT just yet (we're held back because of eCS); and perhaps this fix would be useful for other users as well?

Could not get configured mojo for org.apache.maven.plugins:maven-checkstyle-plugin:2.17:check {execution: check-license}

Plugin org.apache.maven.plugins:maven-checkstyle-plugin:2.17 or one of its dependencies could not be resolved: 

Could not find artifact com.sun:tools:jar:1.7.0 at specified path C:\Program Files\Java\jre1.8.0_25/../lib/tools.jar

解決方案：在Eclipse中將JRE替換成JDK便可.